To　optimize　the　seismic　performance　of　continuous　girder　bridges,　this　paper　proposes　a　multi-level　seismic　fortification　objective　for　continuous　girder　bridges　with　self-centering　functional　separation　bearings　(SC-FSB)　and　safe-belt　devices　(SBD).　Based　on　the　multi-level　seismic　fortification　concept,　these　devices　exhibit　different　mechanical　behaviors　under　varying　seismic　requirements,　thereby　protecting　the　primary　components　and　enabling　a　transition　in　the　restraint　system.　For　this　investigation,　a　three-span　continuous　girder　bridge　was　chosen　as　the　case　study.　Finite　element　models　of　both　the　original　bridge　and　the　seismic-isolated　bridge　were　established.　An　elastoplastic　time-history　analysis　was　performed　under　four　levels　of　seismic　excitation　across　different　site　categories.　The　results　indicate　that　continuous　girder　bridges　equipped　with　SBD　and　SC-FSB　exhibit　significant　improvements　in　internal　forces　under　varying　earthquake　intensities,　showcasing　distinct　grading　characteristics.　Even　if　the　activation　sequence　of　the　two　devices　differs　from　the　predetermined　order　in　rare　cases,　they　still　offer　protective　effects　to　the　piers,　ensuring　the　structural　safety　of　bridges.　Continuous　girder　bridges　with　SBD　and　SC-FSB　successfully　meets　the　multi-level　seismic　fortification　objectives　and　satisfies　the　performance　requirements　at　each　level.　©　2025　Institution　of　Structural　Engineers